Surgical instrument having staple head adapted for rib insertion

ABSTRACT

A surgical stapling instrument with a remotely articulated staple head assembly on a rotatable support shaft. A joy stick mounted to the shaft of the instrument near the handle allows for remote articulation of the staple head assembly. The staple head assembly includes a narrow contour for insertion between adjacent rib pairs without rib spreading. The staple head assembly further includes a reloadable staple cartridge which may be replaced with differently sized staples of a second cartridge. A closure trigger clamps tissue prior to stapling and cooperates with a second trigger that performs the staple firing operation. The triggers include a safety lock mechanism for preventing premature staple firing.

This is a division of application Ser. No. 08/219,846, filed Mar. 30,1994, now abandoned.

FIELD OF THE INVENTION

The present invention generally relates to a surgical instrument forapplying surgical fasteners to tissue and, more particularly, to asurgical stapling instrument with an articulated stapling head assemblymounted on a rotatable support shaft to provide more convenient accessto restricted surgical sites. Also, this invention relates to a linearsurgical stapling instrument including an improved stapling headassembly which is compact in construction, and to an improved actuatorhandle assembly for closing and firing the stapling head assembly.

BACKGROUND OF THE INVENTION AND PRIOR ART

In recent years, there has been an increasing number of surgeons usingsurgical staples, rather than conventional sutures, for closing surgicalincisions. In part, this is because the use of surgical staples andsurgical stapling instruments has made many previously difficultsurgical procedures much simpler to perform. Of more importance,however, is that the use of surgical staples significantly reduces thetime required for performing most surgical procedures, and thereforereduces the length of time during which the patient must be maintainedunder anesthetic. Many types of surgical stapling instruments have beendevised for different surgical procedures. An added benefit of certainsurgical stapling instruments is their ability to be usedfluoroscopically or endoscopically, reducing the size of the incision,the amount of patient discomfort, and the amount of recovery time.

The present invention is directed to a surgical instrument for applyingsurgical fasteners to internal organs and tissues such as the lung,esophagus, stomach, duodenum, and intestines. The invention is embodiedin a linear surgical stapler which permits access to restricted surgicalsites, e.g., the thoracic region and the pelvic area of the human body.

In its earliest form, the linear surgical stapling instrument was apermanent, multi-use instrument, and the surgical staples were manuallyloaded into the instrument one at a time.

A subsequent improvement in linear surgical stapling instruments was thedevelopment of presterilized, disposable loading units or staplecartridges.

Several types of surgical fastener applying instruments are known forapplying surgical fasteners to body tissue clamped between relativelymovable fastener holding and anvil portions of the instrument. Thesurgical fasteners may be metal staples as shown, for example, in U.S.Pat. No. 3,275,211, or consist of non-metallic resinous materials asshown, for example, in U.S. Pat. No. 4,402,445. In the case of metalstaples, the staple legs are typically driven through the tissue andformed by an anvil to secure the staples in the tissue. In the case ofnon-metallic fasteners, each fastener may initially consist of twoseparate parts, i.e., a fastener part disposed in the fastener holdingpart of the apparatus, and a retainer part disposed in the anvil part ofthe apparatus. The leg or legs of the fastener parts are driven throughthe tissue and interlock with the retainer parts to secure the fastenersin the tissue. Although most surgical staples are biologically inert andremain permanently in the body, biologically absorbable metal surgicalstaples are known. Surgical fasteners of non-metallic resinous materialscan also be made either biologically absorbable or non-absorbable.

The surgical instrument of the present invention is not limited to usewith any particular type or form of fasteners. The various surgicalfasteners mentioned above represent examples of the types of fastenerswhich can be used with the instrument of the present invention. Thus, asused herein, "surgical fastener" is a term which is generic to all ofthe above types of fasteners. Similarly, as used herein, "fastenerholder" and "anvil" are terms which, except for certain improvementsdescribed hereinafter, are generic to surgical instruments for applyingall of the above types of fasteners.

In the prior instruments for applying surgical fasteners to tissueclamped between the fastener holding and anvil portions of theinstrument, a distal fastener applying assembly is rigidly connected tothe proximal actuator portion of the instrument. More recently, however,there has been increasing interest in instruments in which theconnection between the fastener applying assembly and the actuatorassembly is not completely rigid.

Also, in view of rising hospital costs, there has been anever-increasing interest in disposable surgical stapling instruments toeliminate as much work as possible, i.e., disassembly, cleaning,reassembly, sterilization and the like, and to be more efficient, whileat the same time, not having to compromise the surgical procedures.

SUMMARY OF THE INVENTION

The present invention achieves an improved surgical instrument forapplying surgical fasteners, such as staples, to human tissue, which isparticularly suited for applying one or more rows of fasteners across atissue lumen to produce a fluid-tight closure of the lumen. The surgicalinstrument of this invention is intended for use in thoracic andabdominal surgical procedures in which single fire surgical staplers arecurrently used and where access to the surgical site is restricted. Forexample, the surgical instrument can be used in the following types ofprocedures: (1) a double stapling technique, especially for a lowanterior re-section, (2) closure of the bronchus during a lobectomy orpneumonectomy, (3) closure of the esophagus in esophageal procedures,and (4) closure of the pulmonary blood vessels during a lobectomy orpneumonectomy.

The surgical instrument in the present invention comprises a shaftassembly including a support shaft section and a knuckle forarticulatably mounting a fastener applying assembly at the distal end ofthe support shaft with respect to a proximal actuator handle assembly.The fastener applying assembly includes a fastener holder for holdingand applying one or more surgical fasteners, a stationary anvil forclamping the tissue using the fastener holder, and a driver for drivingthe fasteners from the fastener holder into the tissue clamped by thefastener holder against the anvil. The actuator handle assembly includesmeans for clamping the tissue, actuating the driver, and releasing thetissue after staple forming. The fastener applying assembly is remotelyarticulated with a joy stick assembly mounted on the support shaft nearthe proximal end of the instrument. The fastener applying assembly mayalso be rotated about an axis generally parallel to the longitudinalaxis of the support shaft.

In another embodiment of the invention the fastener holder isreloadable, having a removable staple cartridge that may be replacedwith a new staple cartridge.

In yet another highly preferred embodiment of the invention, theactuator handle assembly includes a first and second trigger, the firsttrigger being adapted for closing the fastener holder and anvil relativeto each other for tissue clamping and the second trigger being adaptedfor driving the surgical fasteners into the tissue that has beenclamped.

In still another preferred embodiment of the invention, the fastenerapplying assembly is sized and contoured for insertion between humanribs without the use of rib-spreading devices.

In yet another preferred embodiment of the invention, a flexible cableis used for transferring work from an actuator assembly on the handle ofthe device to the distal end of the device. This transfer of work, mayinclude, for example, capturing, clamping, and releasing the tissue anddriving the surgical fasteners. In a highly preferred embodiment of theinvention, the flexible cable comprises a continuous loop ofmulti-strand braided cable such as Vectran®.

These and other embodiments of the presently preferred invention willbecome more readily apparent as the following detailed description ofthe preferred embodiments proceeds, particularly with reference to thefigures.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, aspects and advantages will be betterunderstood and more readily apparent to those of ordinary skill in theart as the following detailed description of the preferred embodimentsof the invention proceeds, particularly with reference to theaccompanying illustrative figures, in which:

FIG. 1 is a cross sectional, transparent, elevational view of apreferred embodiment of the present invention.

FIG. 2 is a cross sectional, transparent, elevational detail of apreferred staple head assembly of the present invention.

FIGS. 3A and B are exploded isometric views of a preferred embodiment ofthe present invention.

FIG. 4 is a transparent top plan sectional view of a preferredarticulation assembly of the present invention.

FIG. 5 is a cross sectional, transparent, side elevation of thearticulation assembly of FIG. 4.

FIG. 6 is an isometric view of another preferred embodiment of theinvention having a sweeping articulation assembly.

FIG. 7 is a top plan partial cross sectional view of the articulationassembly of FIG. 6, taken along lines 7--7.

FIG. 8 is a side elevational partial cross sectional view of thearticulation assembly of FIG. 6, taken along lines 8--8.

FIG. 9 is a cross sectional detail of the encircled portion of FIG. 6.

FIG. 10 is a cross sectional view of a preferred pressure seal for onepreferred embodiment of the invention.

FIG. 11 is a breakaway sectional view of another preferred pressure sealfor a preferred embodiment of the invention.

FIG. 12 is a cross sectional view of the embodiment of FIG. 11 takenalong lines A-A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1, 3A and 3B, the present invention is embodied in asurgical stapling instrument, generally 50, which includes a distalstapling head assembly, generally 60, connected by a support shaftassembly, generally 70, to a proximal actuator handle assembly,generally 80. The stapling head assembly 60 includes a movable jawmember 62 which supports a staple cartridge 64, and a stationary jawmember 66 which supports a staple-forming anvil 68. The staple cartridge64 holds one or more rows of staples 65 which are driven against theanvil 68 and formed into a B-shaped configuration to fasten tissuetogether. For example, fourteen (14) staples may be held in the staplecartridge 64 and arranged in three (3) staggered rows. It will beunderstood by persons of ordinary skill in the art that the surgicalstapling instrument 50 can be adapted to operate with two-part surgicalfasteners instead of staples.

The fastener applying assembly 62 is mounted in a hinge-like fashion ona pivot connection or articulation joint, generally 72, which permitsthe stapling head assembly 60 to pivot or articulate about a verticalaxis 52 into different angular orientations relative to a center line orlongitudinal axis 54 of the support shaft assembly 70. Preferably, thepivot connection 72 is arranged to allow the stapling head assembly 60to pivot about the vertical axis 52 in fifteen degree increments. In thepreferred embodiment, the stapling head assembly 60 is pivotable eitherclockwise or counter-clockwise about the vertical axis 52 to positionsoriented at +/-15°, +/-30°, +/-45°, +/-60°, and +/-75° relative to thelongitudinal axis or centerline 54. This articulation of the staplinghead assembly 60 is achieved remotely with respect to the stapling headassembly 60 via a joystick 202 mounted to the shaft 70 near the handle80.

The support shaft assembly 70 is rotatably mounted on the actuatorhandle assembly 80 for rotation about the longitudinal axis orcenterline 54. Preferably, the support shaft assembly 70 is rotatableover a range of 180° or more about the centerline 54. A rotation knob 82is rotatably mounted at the distal end of the actuator handle assembly80 to allow the support shaft assembly 70 to be placed in a plurality ofdesired rotational orientations.

The shaft assembly 70 includes a tubular support shaft 74 rotatablymounted on the actuator handle assembly 80 and including a pivot bracket75 at the distal end of the shaft 74. The pivot bracket 75 may be eitherintegrally formed with the shaft 74, or may comprise a separatecomponent fastened to the shaft 74. The pivot bracket 75 rotatablyreceives a knuckle pin 76 which is fastened to the stapling headassembly 60. Preferably, the tubular support shaft 74 and the pivotbracket 75 are made of aluminum or a polymeric material, such asVectra®.

The actuator handle assembly 80 includes a pivotally mounted closuretrigger 84 for closing the movable jaw 62 toward the fixed jaw 66 toclamp a section of tissue between the jaws 62 and 66. The actuatorhandle assembly 80 also includes a pivotally mounted firing trigger 86for actuating the stapling head assembly 60 to drive the staples fromthe staple cartridge 64 through the tissue and to form the staplesagainst the anvil 68. The firing trigger 86 is preferably pivotallymounted to the closure lever 84, via a pivot 20. The closure trigger 84includes a shroud 22 providing the user greater comfort and gripability.The shroud 22 includes an opening for receiving a lock catch 24 on thefiring trigger following a staple firing cycle. The shroud 22 furtherincludes a spring-loaded lock/release slide 26, which is slidablyreceived within the shroud. The lock/release slide 26 engages the lockcatch 24, locking the firing trigger 86 to the closure trigger 84 aswill subsequently be described. The lock/release slide 26 may be slid torelease the lock catch 24 and therefore the firing trigger 86 fromengagement with the closure trigger at the conclusion of a staple firingcycle.

As shown in FIGS. 1 and 3, the actuator handle assembly 80 includes apair of hollow handle sections 90 and 92 made of plastic material andadapted to fit together. Each of the handle sections 90 and 92 includesa depending handle grip 96.

Referring to FIGS. 1 and 3-5, the rotation knob 82 has two indentedfinger grips 83 at diametrically opposed positions to facilitate themanual rotation of the control knob 82 by the surgeon. Preferably, thecontrol knob 82 is mounted for rotation over a range of 180° or moreabout the longitudinal axis 54 of the support shaft assembly 70. A pairof resilient cams 87 are arranged to engage a set of teeth 77 on theinside of the handle sections 90, 92. The cams 87 and the teeth 77cooperate in detent fashion to lock the shaft 74 against rotation, butto allow rotation of the shaft 74 in incremental rotational positionsupon turning the rotation knob 82 to overcome the forces of lockingengagement of the cams 87 with the teeth 77. The cams 87 and thecircumferential teeth on the handle sections 90, 92 provide a detentmechanism which defines a plurality of angular positions for rotation ofthe shaft assembly 70.

The following is a more specific description of particular portions,features, and components comprising highly preferred embodiments of theinvention.

Referring to FIGS. 1 and 3A, the actuator handle assembly 80 includes anactuator mechanism, generally 100, contained within the hollow plastichandle sections 90 and 92. Preferably, the components of the actuatormechanism 100 consist of rigid materials, for example, metals, such asstainless steel or aluminum, or a plastic, such as reinforced nylon. Theactuator mechanism 100 includes a pair of outer chassis plates 102 whichare similar in shape to the handle sections 90 and 92. Each of thehandle sections 90 and 92 is provided with a set of internal flanges orribs 93 which support the chassis plates 102 in a fixed position withinthe actuator handle assembly 80 when the handle sections 90 and 92 arefitted together. The chassis plates 102 are fastened together in aspaced parallel relationship by a pair of transverse connecting pins orshoulder rivets 104 located adjacent to the distal ends of the chassisplates 102 and by a set pin or shoulder rivet 106 extending transverselybetween a pair of depending grip portions 108 of the chassis plates 102.An upper connecting pin 110 joins the top middle portions of the chassisplates 102 together. A lower connecting pin (not shown) joins the bottommiddle portion of the chassis plates 102 together. Each of the pins 104,106, 110 support other components of the actuator mechanism 100 as willbe described subsequently.

The actuator mechanism 100 includes a pair of closure lever plates 114each including a pivot hole 116 for receiving the connecting pin 110 topivotally support the closure lever plates 114 for pivotal movementrelative to the chassis plates 102. The closure lever plates 114 aresecured together in a spaced parallel relationship by a transverseconnecting pin 118 which rotatably supports a pulley 120. The closurelever plates 114 include elongated depending lever portions 122 whichare contained inside a hollow plastic closure lever shroud 22 to achievethe closure lever 84 of the actuator handle assembly 80.

The actuator mechanism 100 includes a closure control linkage comprisinga toggle link 155 pivotally connected to the distal end of the closurelever plates by a pair of transverse pivot pins 158 (one shown),extending in opposite directions from the upper end of the link 155. Theouter ends of each pivot pin 158 extend into a hole 160 in the closurelever plate 114. Another transverse pivot pin or follower pin 163 passesthrough the lower end of the link 155 and extends into an inclined guideslot 156 formed in each of the chassis plates 102. Each of the guideslots 156 includes an upper distal section 153 and a lower proximalsection 154 which overlap and define a detent or shoulder 157 in theguide slot 156.

A closure cable 170, preferably comprising a continuous loop of braidedVectran® cable, manufactured by Hoechst Celanese of Charlotte, N.C.,extends from an anchor pin 171 in the toggle link 155 around thetransverse pivot pin 163 and around a two-piece pulley sheave 172. Thepulley sheave 172 rotates in a lubricated bearing in each of the chassisplates 102, and is expanded or retracted, as needed, acting as atensioning modulator for the closure cable 170. Optionally, a tensionlink 172A having a tension pin 172B may be used as illustrated in FIG.3. The toggle link 155 applies tension to the closure cable 170 when theclosure lever plates 114 are actuated by the closure control lever 84.The closure cable 170 extends over the lower coupling pin 104 andthrough an opening 150 formed in the shaft connector 151.

As illustrated in FIG. 3A, the closure cable 170 passes through theapproximate center of the distal end of the actuator handle assembly,through the control knob 83, and through the hollow support shaft 74.The cable 170 is preferably coated with a lubricant, such as silicone,to reduce friction. The cable 170 continues through a lower channel 71in the knuckle pin 76 and into the interior of the staple head assembly60 as illustrated in FIG. 2. As illustrated in FIGS. 2 and 3B, theclosure cable 170 continues through a hole or channel 42A in the body ofthe staple head pilot 42 to the distal end of the staple head assembly60 and passes around a head pulley 180 rotatively mounted via a headpulley axle 181 passing through to the anvil side plates 67 whichsupport the anvil 68 on either side thereof. The closure cable 170reverses direction at the head pulley 180, making a 180° bend, andcontinues through the staple head assembly 60, passing through anopening spring 189, which biases the movable jaw 62 apart from the anvil68. The closure cable 170 terminates at an anchor pin or closure rivet182.

As the closure trigger 84 is pulled proximally toward the handle 96, theclosure cable 170 is also pulled rearwardly, which causes the distance Dbetween the axis of the head pulley 180 and the anchor pin 182 toshorten, pulling the movable jaw 62 toward the fixed jaw 66.

The movable jaw 62 includes a double shoulder roller pin 173 that iscaptured by a horizontal slot 174 in each of the anvil side plates 67.This slot 174 is actually disposed at a slight incline with respect tothe axis 54 of the shaft 74. The double shoulder roller pin 173 is alsoretained within a forward slot 175 in each of the head plates 63 oneither side of the movable jaw 62. As the movable jaw 62 proceedsdistally, toward the anvil 68, the double shoulder roller pin 173, inconjunction with the slots 174 and 175, and the stationary pin 176 inconjunction with the slots 175A assist in orienting the clamping surface190 of the staple cartridge 64 generally parallel to an opposing surfacecomprising the anvil 68.

Referring to FIGS. 2 and 3B, each of the head plates 63 of the movablejaw 62 further includes a dogleg slot 175A which receives a stationarypin 176 passing through a hole 177 in a pair of pin placement arms 178.Each pin placement arm 178 includes an upper slot 179. A placement pin185, slidably positioned in the movable jaw 62, includes a horizontalalignment pin 186 that passes through the placement pin 185 and throughboth the upper slot 179 in the pin placement arm 178 and a horizontalupper slot 187 in the head plate 63. The alignment pin 186 is retainedwith a groove washer 186A. As the movable jaw 62 proceeds distallytoward the anvil 68, the pin placement arm 178 is forced to rotate aboutthe stationary pin 176 in a clockwise direction, which forces theplacement pin 185 to move distally toward the anvil 68.

By the time the transverse pivot pin 163 of the toggle link 155 has cometo rest behind the inclined shoulder portion 157 of the inclined guideslot 156, by virtue of the closure trigger 84 being pulled rearwardly,the placement pin 185 has emerged from the movable jaw 62 and becomesseated within a hole 188 in the upper end of the anvil 68. At thispoint, any tissue positioned between the clamping surface 190 and theanvil 68 is captured by the placement pin 185, in combination with theclamping surface 190 and anvil 68.

The stationary pin 176 acts as a pivot about which the pin placement arm178 may rotate. This rotation is achieved by virtue of a V-shaped slot183 in the head plate 63. A short pin 184 near the leading edge of thepin placement arm 178 rides within the V-shaped slot 183. As the movablejaw 62 moves toward the anvil 68, this short pin 184 is forced along anarcuate path roughly corresponding to that of the curved portion of theV-shaped slot 183. This in turn causes the upper section of the pinplacement arm 178 to rotate, which, through the upper slot 179, causesthe alignment pin 186 to slide along the placement pin slot 187, forcingthe placement pin 185 toward the anvil 68.

As the closure trigger 84 continues to be pulled toward the handle 96,the clamping surface 190 of the movable jaw 62 clamps down against thetissue captured between the clamping surface 190 and the stationaryanvil 68. At the same time, a trigger lock 165 in the handle assembly80, which is biased forwardly by a spring 166, begins to pivot in aclockwise direction (FIG. 1) about a pivot pin 167 that passes throughthe chassis plates 102. A guide pin 168 in an upper leg of the triggerlock 165 rides in an arcuate slot 169 in the chassis plates 102. Therear of the elongated lever portion 122 of the closure trigger 84includes a flange 123, which forces the trigger lock 165 to pivot aboutthe trigger lock pivot pin 167 as the closure trigger 84 is pulledtoward the handle 96. Upon complete closure of the closure trigger 84,the flange 123 rides over the guide-pin 168. The guide pin 168 in turnis pulled forward by the biasing spring 166, coming to rest at theforward end of the arcuate slot 169, where it retains the flange 123 byseating in the notched portion 123A thereof. Once this position has beenachieved, the clamping cycle is complete, and the closure lever 84 islocked into place, in a substantially vertical position, parallel to thehandle 96.

The trigger lock 165 is engaged by a release button 140, which can bedepressed to release the trigger lock 165, as will now be described. Therelease button 140 includes a pivot pin 141 passing through a hole inthe chassis plates 102. The release button 140 further includes arearward flange 142, which is captured by a pin or rib 143 in the handlesections 90, 92. The release button 140 further includes a forwardflange 149 that abuts the trigger lock 165 when the release button 140is depressed.

In order to utilize the release button 140, it is first necessary toovercompress the closure trigger 84 toward the handle 96, therebyreleasing the pressure of the closure trigger flange 123 on the triggerlock guide pin 168. Once this has been accomplished, the release button140 may be depressed, forcing the guide pin 168 toward the rear of thearcuate slot 169, clearing the flange 123. This, in turn, allows themoveable jaw 62 to return to an open position by virtue of the openingspring 189, returning the closure trigger 84 to an open position.

A highly desirable feature of the present invention is that the staplesmay not be fired until the closure trigger 84 has been fully engaged,thereby clamping the tissue to be stapled. Once this has beenaccomplished, as previously described, the firing sequence is ready totake place.

As the closure trigger 84 is pulled toward the handle 96, the firingtrigger 86 begins to descend from its initially horizontal position,ultimately achieving an orientation of roughly forty five degrees (45°)with respect to the longitudinal axis 54 of the shaft 70. The closuretrigger 84 and firing trigger 86 work in cooperation with one another byvirtue of a trigger pin 85 that passes through both the closure lever122 of the closure trigger 84 and the proximal end of the firing trigger86. This trigger pin 85 rides within an arcuate slot 88 contained in theclosure lever 122. As the closure trigger 84 is drawn rearwardly, thetrigger pin 85 is forced to ride up along the rear of a bow tie-shapedopening 89 in the chassis plates 102. The closure lever plate 114 andtherefore the closure lever 122 rotate about the connecting pin 110,which also serves as a pivot. After the closure trigger 84 has beenfully closed, the trigger pin 85 comes to rest at a position 89Acorresponding to the upper rear corner of the bow tie-shaped slot 89. Atthis point, the arcuate slot 88 has rotated forward, such that thetrigger pin 85 is free to advance as the firing trigger 86 is pulled.

The firing trigger 86 is biased apart from the closure trigger 84 by abiasing spring 91.

A firing cable 30, which may be the same type of cable used for theclosure cable 170 previously described, is anchored to the firing pin 85by looping the firing cable 30 around the firing pin 85 as illustratedin FIGS. 1 and 3A. This loop of the firing cable 30 is retained in thefiring pin 85 by a pair of flanges 86A on the firing trigger 86. The twostrands of firing cable 30 wrap around a pulley 120 and pass over atensioning spring 105 anchored by the transverse connecting pins 104.The firing cable 30 continues through the device by passing through theshaft 74 and through a channel 73 through the knuckle pin 76 asillustrated in FIGS. 2 and 3B.

As best seen in FIGS. 2 and 3B, the firing cable 30 enters the movablejaw 62 horizontally, looping around the underside of a driver return pin40 that passes through a driver return spring 40A. The firing cable 30changes direction at the base of the driver return pin 40 and proceedsvertically to a firing link pin 22. The firing link pin 22 passesthrough the upper end of a dog-bone shaped firing link 35 and through avertical slot 35A and the head plates 63. A second firing link pin 22Apasses through the lower portion of the firing link 35, through a strongback plate 33, and through a horizontal slot 33A in the head plates 63.The strong back plate 33 is received by a staple driver 44, which drivesstaples 65 from the staple cartridge 64.

The staple driver 44 is slidably received within a staple head casing 43as illustrated in FIG. 3B. The staple head casing 43 includes a pair offlanges 43A for slidably receiving the removable/reloadable staplecartridge 64. This is accomplished by a pair of complementary flanges64A in the staple cartridge 64, which slide within grooves in theflanges 43A of the staple head casing 43.

As seen in FIG. 2, the clamping surface 190 of the staple cartridge 64includes one or more projections 191 which abut the innermost surface ofthe anvil 68, creating a predetermined space between the clampingsurface 190 and the anvil 68. This space is roughly equivalent to theheight of the projections 191. The height of the projections 191determines the size of the staple formed by the stapling procedure, aswill be subsequently described.

As shown in FIG. 3B, a pilot 42 having a tapered frontal portioncomprises the leading edge of the staple head assembly 60. This pilot 42is sized and shaped to a narrow, tapered contour, to provide access ofthe staple head assembly 60 between adjacent ribs of a patient withoutthe need for rib-spreading techniques or instruments as was necessary inthe prior art. This narrow contour of the pilot 42 is made possible byvirtue of the unique combination of elements of the present invention,including by way of example, the stationary anvil 68, the tight-radiusedpulley 180 allowing for the reverse direction of the closure cable 170,and the use of a sufficiently flexible closure cable 170 that does nottake a set following the 180° bend about the pulley 180.

The staple firing operation of the present invention proceeds asfollows. After the closure trigger 84 has been fully closed aspreviously described, the operator grasps the firing trigger 86 andpulls same toward the handle 96. This causes the firing cable 30 to bepulled rearwardly about the pulley 120, which causes the verticalportion of the firing cable 30 to pull the firing link pin 22 verticallydownwardly in the slot 35A. This, in turn, pushes the lower portion ofthe firing link 35 and lower firing link pin 22A horizontally throughthe horizontal slot 33A, which drives the strong back plate 33 towardthe anvil 68. The strong back plate 33 in turn drives the staple driver44 into the staple cartridge 64, which causes staples 65 to be driveninto the anvil 68, where they are formed in and about tissue clampedbetween the anvil and the clamping surface 190.

The degree of lateral movement of the staple driver 44 is limited by thebase of the driver 44, which supports staple driver arms 44A, which basecontacts a rearward surface of the staple casing 43 upon completion of afiring cycle. Alternatively, the lateral movement of the staple driver44 may be limited by the length of the link 35 or the length of thehorizontal slot 33A. As previously described, the forward or lateralmovement of the staple cartridge 64 is limited by the projections 191.Thus, by varying the height of the projections 191 from one staplecartridge to the next, the relative size of staples being used and/orformed may be varied as well.

As previously discussed, when the staple firing trigger 86 is fullyclosed, a lock catch 24 on the firing trigger 86 engages a lock/releaseslide 26 on the closure trigger 84. Once this locking is achieved, therelease button 140 must be deployed to release the triggers 84 and 86from a vertical position. At this point, the lock/release slide 26 maybe deployed to release the firing trigger 86 from the closure trigger84.

When the firing trigger 86 is released, the firing cable 30 movesdistally, or forwardly, within the staple head assembly 60, releasingthe compressive forces placed on the driver return pin 40 and driverreturn spring 40A, causing the driver return spring 40A to extendupwardly, forcing the driver return lever 34 upwardly, causing thefiring link 35 to pull the strong back plate 33 and staple driver 34rearwardly, away from the anvil 68.

Referring to FIGS. 1 and 3A, a highly preferred embodiment of theinvention includes a safety lock 53. The safety lock 53 includes a pivot55 that passes through a hole in the chassis plates 102. The safety lock53 includes a recess 56 that receives the trigger pin 85 passing throughthe firing trigger 86. The recess 56 precludes actuation of the firingtrigger 86 until the closure trigger 84 is pulled vertically and snapsinto place proximate the handle 96. Once this has occurred, the safetylock 53 rotates about the pivot 55 upwardly such that the recess 56becomes substantially aligned with the arcuate slot 88, clearing apathway for the trigger pin 85 to pass, thereby allowing actuation ofthe firing trigger 86.

The safety lock 53 is biased by a safety lock spring 51. Upon completionof the firing cycle and return of the closure trigger 84 and firingtrigger 86 to their open position, the biasing spring 51 pivots thesafety lock 53 back to the position illustrated in FIG. 1. An inclinedshoulder 57 allows the trigger pin 85 to slide past the safety lock 53and return to seat within the safety lock recess 56 as illustrated inFIG. 1.

In a highly preferred embodiment of the present invention, a releasecable 6 is provided, which is anchored to the anchor pin 171 of thetoggle link 155, loops around the connecting pin 110, passes between thetransverse connecting pins 104, through the shaft connector 151, throughthe shaft 74 and loops around the base of the driver return pin 40.

When the physician encounters a jammed staple and/or clamping scenario,the jammay be released by simply deploying the closure trigger 84 awayfrom the handle 96, using the release button 140 if necessary to enabledeployment of the trigger. This procedure pulls the release cable 6rearwardly about the connecting pin 110, which pulls the driver returnpin 40 rearwardly, separating the staple cartridge 64 from the anvil 68substantially as previously described.

In a most highly preferred embodiment of the invention, the staplecartridge 64 is removable and replaceable, allowing the surgicalinstrument 50 to be reloaded with staples contained in a new staplecartridge 64 following a stapling procedure. As illustrated in FIG. 3B,the staple cartridge 64 includes one or more flanges 64A that areslidably received within a groove contained in complementary flanges 43Ain the staple head casing 43. These flanges may further include alocking flange for snapping the staple cartridge 64 in place. Becausethe staple cartridge 64 is removable, it may be replaced by a secondstaple cartridge 64 having differently sized staples, enabling the sameinstrument 50 to apply more than one size of surgical staple. Aspreviously described, the staples 65 may themselves have a differentsize or shape or the projections 191 on the clamping surface 190 of thestaple cartridge 64 may be varied from one staple cartridge to another,varying the height of a staple formed by the stapling instrument.

Preferably, the staple cartridge comprises a unitary piece such asplastic, having one or more channels for slidably receiving the stapledriver as previously described. Because the staple driver 44 is slidablypositioned within the staple head assembly 60, and is retracted from thestaple cartridge 64 following a staple firing cycle as previouslydescribed, the staple driver 44 remains within the staple head assembly60 following removal of the staple cartridge 64.

The cables 6, 30, and 170 of the invention may be fabricated of anysufficiently flexible cable that does not take a set when reversingdirection, for example, by being wrapped around the tightly radiusedpulleys and pins of the present invention. A highly preferred embodimentof the invention utilizes Vectran® cables comprised of multi-strandbraided Vectran® fibers. Because this material is quite slippery, it hasproven helpful to use a continuous loop for each of the cables aspreviously described, both ends of the loop being wrapped aroundappropriate pins or pulleys as discussed herein.

An additional safety feature of the present invention involves theplacement pin 185, which, in addition to providing alignment of thecartridge 64 and anvil 68 also acts as a safety lock, locking the staplecartridge 64 within the staple head assembly 60 during the clamping andstaple firing cycles, preventing the staple cartridge 64 from beingremoved from the staple head assembly 60 until the closure trigger 84 isreleased from its locked position following the clamping operation.

A highly preferred embodiment of the invention incorporates a mechanismfor articulating, and preferably remotely articulating the staple headassembly 60 about the vertical axis 52 of the knuckle pin 76.

As illustrated in FIGS. 1 and 3A, a highly preferred mechanism forarticulating the staple head assembly 60 includes an articulationassembly, generally 210, including a joystick or articulation lever 202having a vertical shaft 201 that extends into the body of the instrument50, passing through the control knob 82. The joystick shaft 201 includesa pair of annular flanges 200. A continuous articulation belt, 9, ridesbetween the flanges 200 of the joystick vertical shaft 201 and passesthrough the hollow shaft 74 to the knuckle pin 76. As illustrated inFIG. 2, the belt 9 is secured to the knuckle pin 76, for example, with apin 9A passing through the belt 9 and being fastened within the knucklepin 76. This pin 9A assists in preventing the belt 9 from slippingduring the articulation operation.

Referring now to FIGS. 4 and 5, the details of a preferred articulationmechanism of the present invention are illustrated. The shaft 201 of thejoystick 202 receives a clutch gear 4, having a series of teeth whichengage a complementary set of notches in a cylindrical bushing 12 whichis biased distally against the clutch gear 4 by an articulation spring3.

A nut 11 is threadably received by threads 74A (FIG. 3B) on the proximalend of the tubular support shaft 74. This nut 11 is captured by flanges82A on the inside of the control knob 82, providing location for the nut11. Flanges 74B on the shaft 74 prevent relative rotation of the controlknob 82 and the shaft 74. Rotation of the nut 11 causes translation ofthe shaft 74 relative to the control knob 82, providing for tolerancecompensation of the assembly. The joystick shaft 201 is rotatablyreceived within the control knob 82 as previously discussed. Thearticulation belt 9 loops around the articulation lever shaft 201 and issecured thereto with a pin 9B to prevent slippage in the same way thatthe pin 9A prevents slippage of the belt 9 around the knuckle pin 76.

The articulation assembly 210 is connected to the handle assembly 80 bya cylindrical shaft connector 151 that has a pair of flanges 151A thatare captured by a pair of capture flanges 102A in the chassis plates102.

When the articulation lever or joystick 202 is rotated, it causes theshaft 201 to rotate, which transfers work via the articulation belt 9 tothe knuckle pin 76, causing the staple head assembly 60 to rotate aboutthe axis 52. In the embodiment of FIGS. 1-5, this articulation occurs in15 degree increments dictated by the teeth of the clutch gear 4 andbushing 12.

The articulation spring 3 releasably retains the clutch gear 4 and hencethe staple head assembly 60 in a particular angle of articulation. Whenit is desired to alter this angle, the operator need only overcome thecompressive forces exerted by the articulation spring 3 on the clutchgear 4 by rotating the articulation lever 202. This causes the clutchgear 4 to displace the bushing 12 rearwardly, until the teeth in theclutch gear 4 disengage from the notches in the bushing 12, recede, androtate to a new set of notches, at which point the bushing 12 slidesdistally toward the clutch gear 4, locking the clutch gear and staplehead assembly 60 in its new articulation position. As the closuretrigger 84 continues toward the handle 96, tension in the closure cable170 compresses the articulation spring 3, causing the articulationassembly 210 to translate proximally, closing the gap 203 between thecontrol knob 82 and the handle sections 90, 92. When this translationoccurs, the shaft connector 151 contacts the bushing 12, preventing thebushing 12 from displacing rearwardly, thus preventing the teeth in theclutch gear 4 from disengaging from the notches in the bushing 12. Thisaction effectively locks the articulation lever or joystick 202, whichprevents movement of the articulation belt 9 and the knuckle pin 76 andtherefore prevents rotation of the staple head assembly 60 about theaxis 52. When the closure trigger 84 is released, the articulationspring 3 returns the mechanism to its original configuration. Thislocking mechanism, when employed, preferably precludes use of theinstrument (i.e., clamping and/or stapling) at articulation positionsother than the increments dictated by the teeth of the clutch gear 4 andbushing 12.

Another highly preferred embodiment of the invention is illustrated inFIGS. 6-9. In this embodiment, an improved device, generally 700, forpivoting, or articulating the staple cartridge 100 with respect to thesupport shaft assembly 70 is illustrated. The device includes a controlknob 702 rotatably mounted on the support shaft assembly 70 proximatethe actuator handle assembly 80. The control knob 702 is preferablymounted to the support shaft assembly 70 and rotates about an axis A4generally perpendicular to the longitudinal axis A1 of the support shaftassembly 70.

The control knob 702 is adapted for transferring rotational motion ofthe control knob to an articulation driver assembly, generally 704, in alongitudinal direction generally parallel to the longitudinal axis A1 ofthe support shaft assembly 70. Preferably, the articulation driverassembly comprises a sleeve 705 rotatably positioned on the supportshaft assembly 70. The sleeve 705 has an annular channel 706 therein. Asillustrated in FIGS. 6-9, the tubular support shaft 74 slidably receivesa pair of rods 707. Each of the rods 707 has a flange 707A extendingperpendicularly from the proximal end of the rod 707. Each flange 707Ain turn passes through and rides along a pair of slots 708 on eitherside of the tubular support shaft 74, the slots 708 preferably beingoriented generally parallel to and coplanar with the axis A1 of theshaft 74. The flanges 707A also ride within the annular channel 706 ofthe sleeve 705. As illustrated in FIGS. 6 and 9, each of the rods 707may slidably ride within a guide 730 inside the tubular support shaft 74for maintaining spacing between the rods 707 and the walls of thetubular support shaft 74.

Referring again to FIGS. 6-8, the control knob 702 preferably includes aworm gear 712 about the control knob axis A4 for transferring rotationalmotion about the control knob axis A4 to rotational motion about thesupport shaft longitudinal axis A1. This is preferably accomplished withan annular gear 713 fastened to the sleeve 705.

As further illustrated in FIG. 8, the annular channel 706 of the sleeve705 has an inclined orientation with respect to the longitudinal axis A1of the support shaft assembly 70. This inclined orientation converts therotational motion of the sleeve 705 and annular channel 706 to thelongitudinal motion of the flange 707A within the slot 708 when thesleeve 705 is rotated.

As best seen in FIG. 9, each rod 707 has connected to its distal end707b a flexible cable 709 which may be pushed and pulled by the rod 707as its flange 707A slides in the slot 708 and as the rod 707 slides inthe tubular support shaft 74. Preferably, each rod end 707B has a blindhole 720, which receives the cable 709 as illustrated in FIG. 9. Asillustrated, the cable 709 is slipped into the blind hole 720 andsecured to the rod 707, for example, with a crimp or an adhesivematerial 722. Each flexible cable 709 is connected at its distal end tothe staple head assembly 60 as illustrated. In making this connection,the cable 709 is fed through the hollow tubular support shaft 74,through the pivot connection 72 and attached to the staple head assembly60 at a point in the plane parallel to that formed by the intersectionof the axes and A1 and A3, but at a point spaced from the axis A3.Preferably, this connection between the cable 709 and the staple headassembly 60 is achieved by passing the cable 709 into a hole or bore inthe staple head assembly 60, with an adhesive or any other acceptablefastening method.

The flexible cables 709 may be fabricated of any materials suited forthe purpose including, by way of example, but not limitation, steel,nitinol, nylon, and fiberglass. The flexible cable 709 preferablyretains good flexing memory.

In a highly preferred embodiment of the invention illustrated in FIG. 9,the flexible cables 709 are slidably received within a flexible sleeve710, which provides reduced friction as the cable 709 is pushed and/orpulled through the tubular support shaft 74. The flexible sleeves 710are preferably fabricated of fiberglass reinforced or steel reinforcednylon, Teflon®, polyethylene, among other equivalent materials known inthe art.

The embodiment illustrated in FIGS. 6-9 is a "push/pull" system. Thatis, when one of the cables 709 is in compression, the other cable 709 isin tension as dictated by the rotation of the sleeve 705. As illustratedin FIG. 6, the length of the cable 709 is relatively short with respectto the length of the tubular support shaft 74 and rods 707, enablingeach cable 709 to be pushed without buckling substantially. Buckling isfurther avoided by the use of the flexible sleeves 710.

In addition to a "push/pull" system, it would also be possible toarrange the embodiment of FIGS. 6-9 in either a "pull/pull" or a"push/push" system, whereby both cables are pulled or pushed,respectively. For example, in a "pull/pull" system, Vectran® cables,similar to those previously described, could be looped around theflanges 707A, which could be replaced with a pin passing through bothslots 708. The distal end of the cables could be looped around anchorpins in the staple head assembly 60, on either side thereof. Thus,pulling one Vectran® cable would articulate the staple head assembly 60in the direction of pull. Pulling the other cable would reverse thedirection of articulation.

The articulation assembly 700 of the invention offers several advantageswith respect to prior articulation devices. The assembly 700 allows acomplete sweep of articulation over the entire range of articulation(generally 0°-75°), rather than the more limited fixed angles ofarticulation provided with a detent mechanism. Additionally, because ofthe use of the worm gear mechanism, with its advantageous gear ratios,preferably greater than 2:1 to prevent back-driving (i.e., a situationwherein external forces on the staple head cause the head to tend towardan undesirable orientation), the degree of articulation is bothprecisely and easily controlled with the turn of the control knob 702.

In another preferred embodiment of the invention, illustrated in FIGS.10-12, the instrument includes a sealing device for minimizing theescape of gases from the body cavity through the shaft of the instrumentto the ambient environment. This is most important in cases whereininsufflation is used to pressurize the body cavity, rendering the organsmore visible to the surgeon. The seal may comprise any number ofdevices, including flaps, check valves, or gelatinous silicon plugs,which need not render the instrument truly airtight. The purpose of theseal is to minimize the amount of air escaping through the body cavityand the instrument while allowing the instrument to be used by allowingthe cables and/or rods passing through the shaft to continue toreciprocate therein. The seal would thus allow for controlled gasescape, creating a pressure gradient involving a higher pressure on theactuator (staple head) side of the seal than on the handle assemblyside. Thus, the rate of controlled gas escape will be within thepressure requirements required for the insufflation equipment tomaintain the necessary pressure for adequate insufflation over theduration of the insufflation procedure.

An example of such a seal is shown in FIG. 10, wherein the seal 300forms a sphincter within the shaft 74, the articulation belt 9 passes onthe outside of the seal 300 and the various actuation cables 6, 30, 170pass through a small hole 300A in the center of the seal 300. In anotherembodiment shown in FIGS. 11-12 the seal 301 has 4 flaps 301A, 301B,301C, 301D. The seal 301 is made from an elastomeric material whichpermits the flaps to be flexible and bend around the cables 6, 30, 170and the articulation belt 9. In yet another embodiment, a plug ofsilicone or other viscous material with relatively high surface tension,may be placed partway inside the shaft filling empty spaces between thecables and belt, providing resistance to gas flow through the shaftwhile still permitting relative motion of the cables and belt.

The invention in its broader aspects is not limited to the specificdetails of the preferred embodiments shown and described, and those ofordinary skill in the art will recognize that the invention can bepracticed with modifications within the spirit and scope of the appendedclaims, including any and all equivalents thereof. Additionally,although certain preferred embodiments of the invention described hereinsatisfy one or more objects and provide one or more advantages asdiscussed above, is expressly contemplated that the invention may bepracticed in spirit without utilizing all of the objects and advantages,and that accordingly, the objects and advantages of the invention formno part thereof, except as such may be embodied by the full scope of thefollowing claims.

We claim:
 1. A surgical instrument for applying one or more surgicalfasteners to tissue, comprising:an articulatable fastener applyingassembly including a proximal moveable jaw, said proximal moveable jawincluding fastener holding means including a reloadable fastenercartridge for holding one or more surgical fasteners, means for drivingsaid surgical fasteners into the tissue, a distal jaw including anvilmeans for forming said surgical fasteners about the tissue, means forcapturing and clamping said tissue prior to forming said fasteners andfor releasing said tissue after forming said fasteners; a shaft assemblyfor articulatably mounting to the distal end thereof said fastenerapplying assembly; an actuator handle assembly mounted to the proximalend of said shaft assembly and including means for actuating said meansfor driving said surgical fasteners wherein said fastener applyingassembly includes pulley means for reversing direction of a pull cable,said pull cable having two ends, said pull cable being anchored at oneend to said fastener holding means and at its other end to actuatormeans of said actuator handle assembly, whereby as said actuator meansis acted upon by a pulling motion, said pull cable translates saidpulling motion of said actuator means into distal motion of saidfastener holding means, thereby moving said proximal moveable jawdistally toward said distal jaw; said fastener applying assembly sizedand contoured for insertion between human ribs without spreading saidribs.
 2. The surgical instrument of claim 1 wherein said pull cablecomprises Vectran®.
 3. The surgical instrument of claim 2 wherein saidpull cable comprises a continuous loop.
 4. The surgical instrument ofclaim 1 wherein said fastener applying assembly is remotelyarticulatable.
 5. The surgical instrument of claim 1 wherein saidfastener assembly is remotely rotatable.
 6. The surgical instrument ofclaim 1 wherein said means for capturing said tissue includes analignment pin operable to reciprocate within said fastener holding meansand seat within said anvil means, thereby capturing said tissue.
 7. Thesurgical instrument of claim 1 wherein said fastener holding means isadapted for receiving at least two different size fasteners.
 8. Thesurgical instrument of claim 7 wherein said fastener cartridge includesone or more spacing means comprising protuberances on a surface thereofabutting said anvil means for maintaining a predetermined spacingbetween said surface and said anvil means and thereby forming a fastenerof predetermined formed size, said reloadable fastener holding meansadapted for receiving multiple fastener cartridges each havingdifferently sized spacing means for varying the size of a formedfastener produced by each respective fastener cartridge.
 9. The surgicalinstrument of claim 1, further including seal means for maintaining apressure gradient between the distal and proximal ends of said shaftassembly.